An Ir alloy is excellent in high temperature strength while ensuring oxidation wear resistance at high temperature. The heat-resistant Ir alloy includes: 5 mass % to 30 mass % of Rh; 0.3 mass % to 5 mass % of an element group A made of at least one kind of element selected from among Ta and Re; and 0 mass % to 5 mass % of an element group B made of at least one kind of element selected from among Co, Cr, and Ni, wherein the heat-resistant Ir alloy includes 5 mass % or less of the element group A and the element group B in total, and wherein, when the at least one kind of element in the element group A includes Re, the at least one kind of element in the element group B is Co alone, Cr alone, or two or more kinds selected from Co, Cr, and Ni.